Apparatus for cementing wells



Oct. 20, 1931. E. v. cRowELL APPARATUS FOR CEMENTING WELLS Filed July 26, 1927 INVENTOR. 2j' 6,0

ATTORNEY.

Patented `Oct. 20, 1931 UNITED STATES APPARATUS FOR CEMENTING 'WEILS Application med July 26,

1U to its lower end and thence upwardly in the surrounding well bore, and then forcing a cementing mixture downwardly through the casing to a predetermined level and thence outwardly through peripheral casing ports to i5 iill the surrounding bore.

ln. practice where the formation is subject to cavings and consequent choking of the well bore as the casing is being lowered, it is usual to clear the well bore by circulating awashing medium, and it has been found essential to proper clearing of a bore in this manner that the mud-Huid forming the washing medium be circulated downwardly through the casing all the way to its lower end and thence outwardly through the lower end of thecasing and upwardly around the same in order to provide or maintain an open bore through which the casing may be lowered.

Consequently it has been found imperative 39 that the peripheral casing parts through which cement is discharged into the surrounding bore subsequent to lowering the casing, he provided with normally closed valvular meanspwhich are not subject to being opened by pressure of the washing medium in the casing and which consequently insure circulation of the washing medium all the way `to the lower end of the casing, thesaid valvular means however being adapted to be 40 opened subsequent to thewashing operation to permit discharge of a cementinggmixture through the open ports, hut preferably including means for preventing return iow of material from the well bore into the casing.

PATENT oFFlc 1927. serial nu. 208,539.

It is therefore theparticular object of the present invention to provide a string of -cas ing with a section having positively closed peripheral ports, and an unobstructed-bore adapted for flow of a lcirculating medium downwardly through the unobstructed bore past the closed ports and around the lower end of the casing and thence upwardly in the surrounding well bore, the closure means for the ports being adapted for engagement by an actuating plug which is lowered in the unobstructed bore of the casing subsequent to the washing operation in order to shift the closure means and open the ports for discharge of a cementing mixture, and the plug being anchored by its engagement with the closure means so as to close the bore of the casing below the open ports and thereby insure discharge of all of the cement outwardly through the open ports and into the surrounding well bore without any of the cement flowing downwardly through the casing below the anchored plug.

It is a further object of the invention to provide for removal of the actuating plug subsequent to the cementing operation so as to again present an unobstructed casing bore, the plug being removable either by employ ing a plug which may be drilled-out or by use of a plug which may be readily recovered from the well by a suitable tool.

It is a still further object of the invention to employ a traveling plug in conjunction with the actuating plug, the traveling plug being forced down the well casing in back of the quantity of cement which is to be discharged into the surrounding well bore so as to force the cement outwardly through the c asing ports -which arev held open by the anchored actuating plug.

It is a still further object of the invention to provide the casing ports with auxiliary valvular means adapted to open by pressure of the material discharged outwardly through the ports when their plug-actuated closure means have been unseated, but adapted to close against return flow of material into the casing from the surrounding well bore irrespective of the position of the plugactuated closure means.

Further objects of the invention will be readily understood from the following de-v scription of the accompanying drawings showing preferred embodiments of the invention and in which: i

Fig. 1 is a vertical section through a well bore showing the invention in position prior to the cemcnting operation.

Fig. 2 is a similar view with the parts in positlon for the cementing operation.

Fig. 3 is a transverse section on the line 3-3 of Fig. 2. v

Fig. 4 is a vertical section through one of the-recoverable plugs, showing the method of removing the same.

Fig. 5 is aview similar to Fig. 1 but showing a modified construction.

A usual string of casing A is adapted t *i be lowered in the well bore B, and the bore of the casing may have a washing medium clrculated downwardly vtherethrough yand upwardly in the surrounding well bore, and

the casing is then cemented-off to provide a standard well construction.

A fixed section 1 of the string of casing is positioned therein at any predetermined level and preferably has a bore of slightly greater diameter than the remainder of the string; and at its lower end the section 1 is .connected to the string by a coupling 2 forming an internal supporting shoulder 3. Medially 0f its length the bore of the fixed section preferably forms an undercut shoulder 4, and ports 5 open through the wall of the fixed section just below this undercut shoulder. closed by a sleeve valve 6 slidable in the lower end of the bore 'of section l with the bore of the sleeve valve forming a uniform continuation of the bore of the string of casing; and the sleeve valve is yieldably shiftedA upwardly to close the ports and abut against shoulder 4 by means of a coil spring 7 upon which the sleeve valve rests and which is in turn supported upon shoulder 3.

The spring 7 retains the sleeve valve in elevated, closed 'position irrespective of pressure in the string of casing, but the sleeve 1s adapted to be lowered against the tension of its spring so as to open ports 5 by means of an actuating plug which is lowered in the string of casing so as to, engage and depress sleeve 6 and then anchor on the sleeve with the ports open.

The actuatingplug when thus anchored closes the bore of the casing just below the open ports 5, and as a consequence a cementing mixture introduced into the string of casing in back, of the anchored plug is prevented from flowing downwardly through the casing The ports 5 are normallypast the plug and is discharged through open ports 5 into the surrounding well bore. A predetermined quantity of the cementing mixture is preferably thus discharged through the open ports, the quantity of ce ment being measured by a traveling plug lowered in the casing in back of the cement, and in order to prevent leakage past either the actuating plug or the traveling plug they are preferably each provided with suitable packing shown at 8 whereby they form a Huid-tight but sliding lit inthe well casing.

The plugs are adapted to be removed subsequent to the cementing operation so as to again provide an obstructed casing bore, and for this purpose the actuating plug 9 and the traveling plug 10 shown in Figs. 1 to 4, and disclosed and claimed in my co-pending application Ser. No. 327,081, filed December 19, 1928, may be recovered from the well by use of a suitable tool, while the actuating plug 9 and the traveling plug 10 shown in Fig. 5 are adapted to be drilled-out for clearing the bore of the casing.

The destructible plugs 9"-10a are preferably solid structures formed of a wood which may be readily drilled through, and the recoverable plugs 9-10 are preferably provided with normally closed valves which are adapted to open when the plugs are withdrawn so as to allow any fluid above the plugs to pass therethrough and thus eliminate all swabbing action.

As an instance of this arrangement the plugs 9-10 have open bores 11 provided with valve seats 12 at their lower ends, and valves 13 are adapted to normally engage the valve seats for closing the bores of the plugs. The valves are retained in closed position by pres sure aboveV the plugs as they are lowered in the well casing, but when the plugs are withdrawn the valves are lifted to open position by operatively engaging their valve stems 14. The valve stems are hollow tubing extending upwardly from the valves andl sliding in guides 15 at the upper ends of the hollow bores of the plugs, and these .stems are adapted for engagement by a 4usual tubing spear C as shown in Fig. 4 when the plugs are to be withdrawn, so that elevation of the valve stems will first open valves 13 and then withdraw the plugs by engagement of depending abutments 16 of the valves against the undersides of valve seats 12.

The` actuating plugs 9-9 have peripheral abutment slips which automatically expand when the plugs have been lowered into the slightly enlarged bore of section 1 in 'order that said slips may impinge against sleeve ,valve 6 for depressing the same to open ports 5 and then anchor the plugs on the sleeve. These abutment slips are shown in Figs. 1 and 5 respectively as pairs of arcuate `slips 17 and 17l` which are adapted to contract in annular recesses' 1 8 and 18a in plugs 9 9* as i, lo

the p Vugs are lowered through the string of casing; and bias springs 19 shown in Fig. 1 or coil springs 19a shown in Fig. 5 are positioned in back of the slips so as to yieldably urge the same to expanded position where they will operatively engage sleeve valve 6.v

Expansion of the slips is pre'feably guided and limited by abutments 2020a on plugs 9-9a slidably engaging in notches 21--21*1L in slips 17-17a. y

In addition to the positive closure means for ports 5 which is formed by the sleeve valve 6 opening only through engagement by the actuating plug, the ports are preferably pro- -vided with auxiliary closure means at the exterior of section 1 of the casing, the said auxiliary closure means being adapted to open by pressure of material discharged outwardly through ports 5 when sleeve valve 6 has been opened, ut automatically closing against back iow of material through the ports and into the casing irrespective of the position of valve 6. The auxiliary closure means are shown as spring strips 25 are i'xed at one end to flattened surfaces 26 at the exterior of casing section '1, with the opposite swinging ends of the strips overlying and normally charged twardly through the. ports is thus adapted swingx the 'strips outwardly as shown in ig. 2 for opening the ports, but as soon as all the material has been discharged through the ports the resiliency of the spring strips again closes the same to prevent back ow into the casing. y

In operation the well casing presents a uniform unobstructed bore prior to thelowering of plug 9-or 9a, with ports 5 closedby sleeve valve 6 which is held in closed position by its spring and irrespective of pressure in the casing. Drilling may then be C0ntined or the casing may be washed down, as for example by the methods disclosed and claimed in my (zo-pending applications, Ser. No. 327,080, filed December 19, 1,928, and Ser. No. 331,411, filed January 10, 1929, the Closed ports 5 preventing passage therethrough of the washing medium and thereby insuring closing ljs 5. Pressure of material disits circulation allthe way to the bottom ofy the casing and outwardly around the lower end of a casing shoe 30 or the like for clear-` ing away obstructing material and thence upwardly in the surrounding well bore. The well bore having been cleared the casing may be lowered to the formation seat and the actuating plug loweredin the casing as shown in Fig. 1. When the .actuating plug reaches the valvesleeve 6 it depresses the same to open ports 5, and by anchoring on the depressed sleeve valve it closes the bore of the casing below the open ports, the parts inthis ,position being shown in Fig. 2. The cementing mixture is then introduced into thecasing, the quantity of cement being measured `by lowering the traveling plug in back of .the bore of the ported section,

bore of the vcasing below the the same, and the traveling plug is forced downwardly-in suitable manner so that the cement ows outwardly through the open ports, the auxiliary valves 25 readily opening by the pressure of the iow for discharge of the cement into the surrounding well bore.

The cement having been discharged the valves25 automatically close to prevent back flow into the casing, and the plugs may then be removed either by drilling them out or recovering the same as previously described,

whereupon the valve 6 will again close and V circulate the washing medium downwardly and around the bottom of the casing and thence upwardly outside the same to wash the casing free, the ports in the casing remaining closed irrespective of the pressure y'in the casing but adapted to be opened by mechanical meanssubsequent to the washing operation when itis desired to cement the well.

Iclaim: 1

1. Well casing having a portedsection with a bore of slightly greater diameter than that of the string of casing, a sleeve vjalve in p a spring adapted to elevate the sleeve valve for closing the port, and a, plug adapted for contraction so that it maggbe lowered in the casing and adapted to expand in the enlarged bore of the ported section so as to engage and depress the sleeve valve or opening the port and anchoring the plug `on the depressed sleeve with said anchored plug closing the open port. l

2. Well casing having a ported section with a bore of slightly greater diameter than the bore of the string of casing, a sleeve valve mounted in the bore of the ported section so as tov leave the entire bore of the casing, unobstructed, yieldable means tending to axially shift the sleeve valve so as to close the port, and means adapted for expansion in the enlarged bore of the ported section so as to` engage/ and oppositely v'axially shift the sleeve valve for opening the port.

ed for expansion in the enlarged bore of the ported section so as to engage and oppositely axially shift the sleeve valve for opening the aus port and closing the bore of the casing below the o en port. 4. with a bore of shghtly greater diameter than that of the string of casing, a sleeve valve in the bore of the ported section, yieldable means tending to axially shift the sleeve valve so as to close the port, and means adated for expansion in the enlarged bore .of t e ported section so as to engage and oppositely axially shift the sleeve valve for openin the port and anchoring said means on the s eeve with said anchored means closing the bore of the casing below the open ort.

In testimony whereof he as aixed his signature to this s ecication.

RD V. GROWELL ell casing having a ported section 

